Hi,
I'm looking at building a pair of high quality sealed monitor speakers for a new studio project and hoping to use drivers which I already have. Here is my proposition; Westra KW202-1328 for the woofers. Can't seem to find much info on these as to whether they will sound nice or not, but they seem to be well made.? Anyone have any experience with them. They have dual 8 ohm voice coils, which may be handy for impedance matching. These go from 30-3000Hz. Here's a data sheet for them: www.pollin.de/shop/downloads/D640527D.PDF
Then for the top end I was hoping to use a pair of Audax HD12x9D25 tweeters. Here's the data sheet: http://www.audax.com/archives/HD12X9D25%20-%20Catalogue%201986.pdf
I would prefer a 2-way system and then bi-amp it. If 3-way might work better then I could use a pair of Audax HD12P25FSM SQ which I have. Can't find a data sheet on them so it'll be trial and error there!
I would really like to know your thoughts on this setup, good or bad. Will it give defined results which are usable in a professional studio? I say professional cos this is no garage studio we're building 🙂. I'm especially unsure of the Westra drivers as I have no idea how they will sound. Could try them in a baffle first I guess. I have attached a photo of them if that's any use in IDing them?
If the Westra's are not worth using another preferred bass driver which I could source cheaply is the KEF SP1014 (early B200). I have a pair of these in sealed Heathkit AS9520 cabs and they sound brilliant and go way down to 20-odd Hz! 😀
I'm looking at building a pair of high quality sealed monitor speakers for a new studio project and hoping to use drivers which I already have. Here is my proposition; Westra KW202-1328 for the woofers. Can't seem to find much info on these as to whether they will sound nice or not, but they seem to be well made.? Anyone have any experience with them. They have dual 8 ohm voice coils, which may be handy for impedance matching. These go from 30-3000Hz. Here's a data sheet for them: www.pollin.de/shop/downloads/D640527D.PDF
Then for the top end I was hoping to use a pair of Audax HD12x9D25 tweeters. Here's the data sheet: http://www.audax.com/archives/HD12X9D25%20-%20Catalogue%201986.pdf
I would prefer a 2-way system and then bi-amp it. If 3-way might work better then I could use a pair of Audax HD12P25FSM SQ which I have. Can't find a data sheet on them so it'll be trial and error there!
I would really like to know your thoughts on this setup, good or bad. Will it give defined results which are usable in a professional studio? I say professional cos this is no garage studio we're building 🙂. I'm especially unsure of the Westra drivers as I have no idea how they will sound. Could try them in a baffle first I guess. I have attached a photo of them if that's any use in IDing them?
If the Westra's are not worth using another preferred bass driver which I could source cheaply is the KEF SP1014 (early B200). I have a pair of these in sealed Heathkit AS9520 cabs and they sound brilliant and go way down to 20-odd Hz! 😀
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Westra is very old, from former East Germany, I think. This is subwoofer model, you can not use it for 2-way system, 3-way system is mandatory. Parallel two voice coils and put it in the sealed box (after the measuring of the TS parameters and calculating the volume of the cabinet!). It will be good for domestic purposes, but definitely not for professional studio!
The same for Heathkit AS 9520 - nice for home, not for professional studio.
For serious work in the professional studio, by Genelec, Adam, or something similar.
The same for Heathkit AS 9520 - nice for home, not for professional studio.
For serious work in the professional studio, by Genelec, Adam, or something similar.
Westra speakers are probably very well suited for a sealed box
but how would they perform is something which can be answered
after taking measurements. I am guessing you could be satisfied
with them if very skillfully crossed with audax at around 2 kHz.
You would probably need to parallel the voice coils for better performance
and end up having a nominally 4 ohm speaker load. For not very loud
listening these would serve well.
thanks for the replies guys 🙂.
OK so if you don't think that these will be worth bothering with, how about this setup instead:
SEAS 33FWKA 13 inch bass driver: http://www.seas.no/images/stories/vintage/pdfdataheet/h097_and_h190_33f-wka_and_dd.pdf
AUDAX HD12P25FSM SQ as mids (could use 2 per cab if needed as I have 2 pairs of them)
AUDAX HD12x9HD25 Tweeters.
The SEAS definitely seem to be of high quality and I believe the above driver types were used in Studio monitors at some point (not sure about the SEAS ones though)
I'm using WinISD beta to run simulations. Probably totally basic compared to what some of you guys are using...?
OK so if you don't think that these will be worth bothering with, how about this setup instead:
SEAS 33FWKA 13 inch bass driver: http://www.seas.no/images/stories/vintage/pdfdataheet/h097_and_h190_33f-wka_and_dd.pdf
AUDAX HD12P25FSM SQ as mids (could use 2 per cab if needed as I have 2 pairs of them)
AUDAX HD12x9HD25 Tweeters.
The SEAS definitely seem to be of high quality and I believe the above driver types were used in Studio monitors at some point (not sure about the SEAS ones though)
I'm using WinISD beta to run simulations. Probably totally basic compared to what some of you guys are using...?
I see that both of you recommend a sealed box, and to parallel the coils, so if I do experiment with the Westras I will do that 🙂. Might just make a small sub out of them or something.
My hope is to eventually soffet-mount the studio monitors, so any advice there re the initial cab building would be most welcome!
My hope is to eventually soffet-mount the studio monitors, so any advice there re the initial cab building would be most welcome!
Well, to put it bluntly: if you don't have above average engineering skills, knowledge and measuring equipment, you can not build a good studio monitor!
It is great fun to build loudspeakers for home, but building professional studio equipment is way beyond the reach of average DIY amateur.
As I wrote before, buy genuine professional studio monitor: Genelec, Adam, ...
It is great fun to build loudspeakers for home, but building professional studio equipment is way beyond the reach of average DIY amateur.
As I wrote before, buy genuine professional studio monitor: Genelec, Adam, ...
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I don't typically like to discourage people, but here I have to agree with Sonce. Either that or build a well documented and proven kit design.
The drivers you've got appear to be ancient. This might not be a problem, but old drivers do deteriorate, their soft parts break down/change properties, some of them can rot away, ferro fluid can dry up etc.
If you wanted to go with something DIY then you'd really want to use new drivers, especially if the setting is for the studio.
I mean it's one thing to build a design with the drivers you have lying around for the spare room as an 'on the side' project. It's another if it's to be used professionally.
I can't even find info on those mids you've got either.
The drivers you've got appear to be ancient. This might not be a problem, but old drivers do deteriorate, their soft parts break down/change properties, some of them can rot away, ferro fluid can dry up etc.
If you wanted to go with something DIY then you'd really want to use new drivers, especially if the setting is for the studio.
I mean it's one thing to build a design with the drivers you have lying around for the spare room as an 'on the side' project. It's another if it's to be used professionally.
I can't even find info on those mids you've got either.
Sonce, I don't think it is not a lack of the above that needs to be discussed here. And although I have not been building speakers for decades or something I am well capable of "engineering" in it's various specialties, have the required measuring equipment, and possibly I am just lacking in some knowledge.
I was simply asking peoples opinions on the drivers that I have, and hoping that people who have actually used them and built systems with them could give me some feedback on what they are like, regardless of whether they fit the grade for studio monitors... But unfortunately I haven't had anyone say they have used them and heard them yet, so I guess I won't know until I try them ;-)...
Good points 5th! 🙂 I will look out for any defects if I go ahead with the build.
I guess I just can't afford to go out and buy a pair of Adam A7's or Focals so I'll just have to work with what I have for now 🙂.Plus I really don't like these small format monitors! Big speakers give big sound, and plenty of low end down to 20Hz or so! 🙂 It is my studio that I need these monitors for BTW, not some job that we're being paid to do...
If anyone has had experience with the drivers that I have, please let me know 🙂
I do not mean to offend you, just pointing out that designing a good studio monitor is not a trivial job. If I was misunderstood, I am apologizing.
I do not have hands-on experience with the mentioned drivers, but we can confidentionaly relay on given measurements. SEAS 33FWKA is much better than Westra. For realy low end you have to put SEAS in a vented box, but do not worry, it's low Qts ensures very good low-end control.
As I recall, Audax HD12x9HD25 tweeter was extensively used in good sounding designs.
I do not have any information on AUDAX HD12P25FSM SQ.
I used the HD 12x9 D25s some 30+ years ago. They were good at the time, though a bit 'tizzy' at the top. Modern tweeters surpass them by a considerable margin.
Hi,
Those Westra look very similar to Tesla drivers.
I think they are good value, and being vintage their value only increases over time.
.
Those Westra look very similar to Tesla drivers.
An externally hosted image should be here but it was not working when we last tested it.
I think they are good value, and being vintage their value only increases over time.
.
No worries Sonce, no hard feelings ;-). Will possibly go with the Seas drivers then and try a reflex box. You are right about the Studio Monitors, it might take me a long time to put something good together, and maybe I need to step into or closer to the 21st century with the drivers I'm using 😛.
Thanks for the further feedback guys 🙂. Yes Elias, they do look very similar to my Westra drivers!
TVM Acoustics, Valašské Meziøíèí - Hlubokotónové
These could be the same mayhaps😱) Cheap like Cz beer😱)
These could be the same mayhaps😱) Cheap like Cz beer😱)
The Audax MHD 12 P 25 FSM SQ was excellent in 1982. By now the flat foam surrounds are only intact by the grace of Luck. I used a few in my high end car audio installs back then. Audax specs a third order xo at 600 so it never was very sturdy.
Thanks for that phivates, that helps a lot, it's not a HD12P25FSM it's an MHD! This yields info with google.
I do not know whether or not one would call it unsturdy, with a highish recommended high pass, just not capable down low. This is typical of flat surround drivers as they do not have any xmax, or at least the coil can have a decent amount of xmax, it's just the surround severely limits the linearity. The Audax itself has a rather low fs of 210Hz, so their recommendation is certainly with regards to keeping the excursion down.
As you pointed out though, after so many years, any foam surrounds will only be intact by shear luck. Most likely because they've been inside a box and not exposed to any UV light. We are of course assuming that vinyvamos has inspected his drivers and knows they are still in good working order!
It would be my guess however that after a little bit of use the foam will probably start to disintegrate. I have used Audax drivers from around that era, some new old stock, and while they seemed perfectly fine when first used, after a year or so the surrounds perished.
This is a bit of a shame because the MHD12P25FSM look like nice drivers. Nice and sensitive with a well controlled paper cone, much like the 33FWKA in fact. Both drivers would work well together with a 600hz 4th order acoustic. Add in a cheap and sensitive modern tweeter, such as the DQ25 from Vifa and providing you could put together a good crossover, you'd have a pretty good system with great bass. The main caveat being if you can design a good xover and measure everything properly.
Of course it's like I said at the start though. Time degrades soft parts, spiders and surrounds. If they aren't intact and you cannot get replacement surrounds, then you're going to have to buy new drivers.
The SEAS, with its rubber surround, is likely to be okay, but you will need to use it some to see. My advice would be to hook it up to a 20Hz signal and run it at half rated xmax for a day or two. We aren't told what xmax actually is, but running it at around 8mm peak to peak, would probably be a safe bet. Let the surround and spider get used to moving for a bit, then measure the T/S parameters and see what they are like. With any luck the driver will measure decently and simulate well.
I do not know whether or not one would call it unsturdy, with a highish recommended high pass, just not capable down low. This is typical of flat surround drivers as they do not have any xmax, or at least the coil can have a decent amount of xmax, it's just the surround severely limits the linearity. The Audax itself has a rather low fs of 210Hz, so their recommendation is certainly with regards to keeping the excursion down.
As you pointed out though, after so many years, any foam surrounds will only be intact by shear luck. Most likely because they've been inside a box and not exposed to any UV light. We are of course assuming that vinyvamos has inspected his drivers and knows they are still in good working order!
It would be my guess however that after a little bit of use the foam will probably start to disintegrate. I have used Audax drivers from around that era, some new old stock, and while they seemed perfectly fine when first used, after a year or so the surrounds perished.
This is a bit of a shame because the MHD12P25FSM look like nice drivers. Nice and sensitive with a well controlled paper cone, much like the 33FWKA in fact. Both drivers would work well together with a 600hz 4th order acoustic. Add in a cheap and sensitive modern tweeter, such as the DQ25 from Vifa and providing you could put together a good crossover, you'd have a pretty good system with great bass. The main caveat being if you can design a good xover and measure everything properly.
Of course it's like I said at the start though. Time degrades soft parts, spiders and surrounds. If they aren't intact and you cannot get replacement surrounds, then you're going to have to buy new drivers.
The SEAS, with its rubber surround, is likely to be okay, but you will need to use it some to see. My advice would be to hook it up to a 20Hz signal and run it at half rated xmax for a day or two. We aren't told what xmax actually is, but running it at around 8mm peak to peak, would probably be a safe bet. Let the surround and spider get used to moving for a bit, then measure the T/S parameters and see what they are like. With any luck the driver will measure decently and simulate well.
Short voice coils are a given with these older drivers. Xmax is 3 or 4 mm for anything in my old spec sheets whether Audax SEAS or Focal. In other ways they are still excellent, but time gets to everything. I've gone around the block more than once trying to dope old foam into surviving another year but one modern bass transient and poof! Lately I've been playing with old Advent stuff and again, drying and stiffening raises tweeter resonance by half. Not too good!
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